DEXA Scan Report Explained: Understanding Your T-Score

Key Takeaways

Your T-score is the most important number on a DEXA scan report — it compares your bone density to that of a healthy 30-year-old adult.
A T-score of -1.0 or above is normal, between -1.0 and -2.5 indicates low bone density (osteopenia), and -2.5 or below means osteoporosis.
DEXA scans are quick, painless, and use very low radiation — about one-tenth of a standard chest X-ray.
Your doctor may also use your FRAX score to estimate your 10-year fracture risk and guide treatment decisions.

A DEXA scan (dual-energy X-ray absorptiometry) is a specialized imaging test that measures how strong and dense your bones are. The scan uses two low-energy X-ray beams to calculate your bone mineral density (BMD) at key sites — typically the lumbar spine and hip.

The entire procedure takes about 10–20 minutes, and the radiation dose is extremely low (approximately 0.001 mSv), which is roughly one-tenth the exposure of a chest X-ray. You simply lie on a padded table while a scanner arm passes over your body. There are no injections, no contrast dye, and no special preparation needed.

The Radiological Society of North America (RSNA) recommends DEXA scans for all women over 65, men over 70, and younger adults with risk factors such as a history of fractures, long-term steroid use, or a family history of osteoporosis.

Understanding Your T-Score

The T-score is the centerpiece of your DEXA report. It compares your bone density to the peak bone mass of a healthy 30-year-old adult of the same sex. The World Health Organization (WHO) established the following classification system:

T-Score	Classification	What It Means
-1.0 or above	Normal	Your bone density is within normal limits
-1.0 to -2.5	Osteopenia (low bone density)	Bones are weaker than normal but not yet osteoporotic
-2.5 or below	Osteoporosis	Significantly reduced bone density with higher fracture risk
-2.5 or below + fracture history	Severe osteoporosis	Osteoporosis confirmed by both density and clinical fractures

For example, a T-score of -1.8 means your bone density is 1.8 standard deviations below the average for a healthy young adult. According to the National Institutes of Health (NIH), the risk of fracture approximately doubles with each 1-point drop in T-score.

What About the Z-Score?

Your report may also include a Z-score, which compares your bone density to the average for someone your own age, sex, and body size. A Z-score below -2.0 is considered below the expected range for your age and may prompt your doctor to investigate underlying causes of bone loss, such as vitamin D deficiency, thyroid disorders, or certain medications.

Z-scores are especially important for premenopausal women, men under 50, and children, where the T-score classification system does not directly apply.

Reading the Rest of Your DEXA Report

Beyond the T-score and Z-score, your DEXA report contains several other important details.

Anatomical Sites Measured

Most reports include measurements for two or three locations:

Lumbar spine (L1–L4): Measures the vertebral bodies in your lower back. Spinal bone loss often appears earliest here.
Femoral neck: The narrow area at the top of your thighbone, one of the most common fracture sites.
Total hip: An average measurement across the entire hip region.

Your doctor will typically use the lowest T-score from any of these sites to make a diagnosis. If your spine T-score is -1.2 but your femoral neck T-score is -2.6, the diagnosis would be osteoporosis based on the hip result.

The Impression Section

Like other radiology reports, your DEXA scan includes an impression — a summary where the radiologist states the overall diagnosis. You might see wording like "Osteopenia at the lumbar spine" or "Normal bone density at all measured sites." This section is what your referring doctor typically reads first.

FRAX Score

Many DEXA reports now include a FRAX (Fracture Risk Assessment Tool) calculation. FRAX combines your femoral neck bone density with clinical risk factors — including age, sex, BMI, smoking status, alcohol use, and fracture history — to estimate your 10-year probability of:

A major osteoporotic fracture (spine, hip, forearm, or shoulder): Treatment is typically recommended if this risk exceeds 20%.
A hip fracture specifically: Treatment is typically recommended if this risk exceeds 3%.

What to Do After Getting Your Results

Understanding your DEXA results is the first step. Here is what to discuss with your doctor based on your scores:

Normal T-score: No treatment is usually needed, but continue weight-bearing exercise, adequate calcium (1,000–1,200 mg/day), and vitamin D (600–800 IU/day). Repeat DEXA in 5–10 years depending on risk factors.
Osteopenia: Your doctor may recommend lifestyle changes, fall prevention strategies, and possibly a repeat scan in 1–2 years to monitor for changes. Medication may be considered if your FRAX score is elevated.
Osteoporosis: Treatment options include bisphosphonates, denosumab, or other bone-building medications. Your doctor will tailor a plan based on your age, fracture risk, and overall health.

If you feel unsure about your results, bring your report to your next appointment and ask your doctor to walk through the numbers with you. Our guide on how to discuss imaging results with your doctor offers practical tips for getting the most out of that conversation.

Frequently Asked Questions

How often should I get a DEXA scan?

For most adults with normal bone density, the American College of Radiology (ACR) recommends rescanning every 5–10 years. If you have osteopenia or osteoporosis, your doctor may recommend scans every 1–2 years to track how well treatment is working.

Is a DEXA scan safe?

Yes. DEXA scans use an extremely low radiation dose — about 0.001 mSv per scan, which is less than the natural background radiation you receive in a single day. According to RadiologyInfo.org, there is no special preparation required and no side effects.

Can a DEXA scan detect conditions other than osteoporosis?

A standard DEXA scan is specifically designed to measure bone density. It does not detect fractures, bone tumors, or other skeletal conditions. However, some newer DEXA platforms can assess body composition (lean mass vs. fat mass) and vertebral fractures using a lateral spine image.

Disclaimer: This article is for educational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional for diagnosis and treatment decisions.

Key Takeaways

Your T-score is the most important number on a DEXA scan report — it compares your bone density to that of a healthy 30-year-old adult.
A T-score of -1.0 or above is normal, between -1.0 and -2.5 indicates low bone density (osteopenia), and -2.5 or below means osteoporosis.
DEXA scans are quick, painless, and use very low radiation — about one-tenth of a standard chest X-ray.
Your doctor may also use your FRAX score to estimate your 10-year fracture risk and guide treatment decisions.

What Is a DEXA Scan?